The present invention comprises a new and distinct cultivar of Rhododendron hybrid used as a flowering shrub or rootstock known by the varietal name ‘Rhodunter 48’. The new variety was discovered in Ahrensburg, Germany. The new variety is the result of a planned breeding program between an unpatented and unnamed plant of Rhododendron fortunei (female parent)×cv. ‘Cunningham's White’ (unpatented male parent). The new variety exhibits matroclinal morphological features. ‘Rhodunter 48’ exhibits distinct but similar leaf venation to both parents, as well as similarities in color and shape. The new variety has been trial and field tested and has been found to retain its distinctive characteristics and remain true to type through successive propagations.